Sodium Phytate?

[KiwiMoose]

Calling all chemists!

This product is now available from one of my suppliers and is being heralded as a natural alternative to EDTA. It acts as a chelator and helps to prevent metal-catalysed reactions, and can help with rancidity and discolouration caused by metals. It also has moisturising properties?

Sounds like a wonder product!

Is this true?

What can you tell me?

 

[Aromasuzie]

I’m not a chemist, but isn’t the reason why DOS occurs is due to rancidity of oils is mainly due to temperature/light/O2 exposure to the oils? I would think if you are using distilled water, then the amount of metal-catalysed reactions occurring within the soap would be low? I’ll certainly be interested to hear from those in the know about the chemistry

 

[ResolvableOwl]

Yes, phytic acid/phytate is a chelator, it is even blamed as an anti-nutrient for its properties to block the body from taking up trace elements when present in food.
But phytate is, just like oils (triglycerides) also an ester by itself (phosphoric acid ester of inositol). I could be wrong, but I know what lye does to triglycerides. So I wouldn't bet on phytate to be indefinitely lye stable, and not being broken down to phosphate (inorganic salt) and inositol (a sugar-like substance).

Is it advertised as unrestricted CP safe? Do they mention advantages over citrate and gluconate (other viable, time-proven lye stable, and no less natural EDTA replacements)?

 

[earlene]

I’m not a chemist, but isn’t the reason why DOS occurs is due to rancidity of oils is mainly due to temperature/light/O2 exposure to the oils? I would think if you are using distilled water, then the amount of metal-catalysed reactions occurring within the soap would be low? I’ll certainly be interested to hear from those in the know about the chemistry

I just read this interesting article this morning, regarding two types of causal factors for rancidity to occur in nutritional oils (or in our case, soaping oils) : Understanding rancidity of nutritional lipids

It talks about oxidative rancidity and hydrolytic rancidity, even microbial rancidity. It also includes the part about metallic ions as catalysts, which was a question someone raised recently as how metals could contribute to DOS, so I bookmarked it for future reference. And future arrived in a matter of a couple of hours!

KiwiMoose, I am definitely not a chemist. But I did find a couple of references that indicate it may or may not work in bar soap up (high pH was my concern). At lotioncrafter it is recommended to adjust pH to 6.0 or less, but that was for non-soap cosmetics. And again in the Alexmo link, the statement that for best performance a pH of 6.0 is desirable, it makes me think it might not be appropriate for soap. And the third link, although it lists several products in which it is used, not one of them is soap. So maybe it doesn't survive lye? I don't really know.

https://lotioncrafter.com/products/sodium-phytatehttps://www.alexmo-cosmetics.de/Chelating-Agent_1http://formulatorsampleshop.com/v/reference/Sodium Phytate Presentation.pdf

 

[DeeAnna]

I’m not a chemist, but isn’t the reason why DOS occurs is due to rancidity of oils is mainly due to temperature/light/O2 exposure to the oils? I would think if you are using distilled water, then the amount of metal-catalysed reactions occurring within the soap would be low? I’ll certainly be interested to hear from those in the know about the chemistry

Yes, high temperature and exposure to light, water, oxygen, and microorganisms are things that cause fats to oxidize and become rancid. But metals operate independently of these other factors. If your soap or fat contains trace metals, the soap or fat will go rancid quicker even if you do everything in your power to exclude light, water, and oxygen and keep the temp low.

Remember soap and fat are natural products and oxidation is a part of the natural process of decomposition. It is normal for fat and soap to oxidize and eventually go rancid. We can delay the process, but we can't stop it.

 

[Johnez]

I just read this interesting article this morning, regarding two types of causal factors for rancidity to occur in nutritional oils (or in our case, soaping oils) : Understanding rancidity of nutritional lipids

It talks about oxidative rancidity and hydrolytic rancidity, even microbial rancidity. It also includes the part about metallic ions as catalysts, which was a question someone raised recently as how metals could contribute to DOS, so I bookmarked it for future reference. And future arrived in a matter of a couple of hours!

KiwiMoose, I am definitely not a chemist. But I did find a couple of references that indicate it may or may not work in bar soap up (high pH was my concern). At lotioncrafter it is recommended to adjust pH to 6.0 or less, but that was for non-soap cosmetics. And again in the Alexmo link, the statement that for best performance a pH of 6.0 is desirable, it makes me think it might not be appropriate for soap. And the third link, although it lists several products in which it is used, not one of them is soap. So maybe it doesn't survive lye? I don't really know.

https://lotioncrafter.com/products/sodium-phytatehttps://www.alexmo-cosmetics.de/Chelating-Agent_1http://formulatorsampleshop.com/v/reference/Sodium Phytate Presentation.pdf

Interesting link (alexmo), from article:

Chelating Agent supports the protection of valuable ingredients from oxidation (e.g. unsaturated oils, fragrance components). It maintains foaming in rinse-off products when hard water is used and prevents precipitation of insoluble salts of fatty acids in soaps.
Best performance is shown at pH 6.

The binding of magnesium and calcium are particularly helpful for shave soaps in hardwater areas, tho I wonder if it's cost effective compared to citric acid. I wonder what exactly the pH is affecting in performance.

 

[ResolvableOwl]

I wonder what exactly the pH is affecting in performance.

Lower pH means less of the phosphate groups have given off their protons = less negative charge = less attraction for positively charged metal ions. The remark of higher pH might indeed point to instability towards alkaline hydrolysis (what chemistry textbooks suggestively call “saponification”). EDTA and citrate are dutiful chelators even at high pH, and stable towards hydrolysis.

Also note that pH 6 means most soap molecules have been converted to free fatty acids – which is a bad idea™ for several reasons. Neutral/acidic conditions are outright incompatible with soap.

 

[Aromasuzie]

Yes, high temperature and exposure to light, water, oxygen, and microorganisms are things that cause fats to oxidize and become rancid. But metals operate independently of these other factors. If your soap or fat contains trace metals, the soap or fat will go rancid quicker even if you do everything in your power to exclude light, water, and oxygen and keep the temp low.

Remember soap and fat are natural products and oxidation is a part of the natural process of decomposition. It is normal for fat and soap to oxidize and eventually go rancid. We can delay the process, but we can't stop it.

Very true. I will often recommend clients use citrus oils in vaporisers or to use low dilutions on leave on body products, as they are high in terpenes, which can easily oxidise, creating peroxide’s. I like using that example as most women have heard of peroxide’s

Does anybody ask their oil suppliers when their vegetable oils are processed?

@earlene, great article.

 

[user 49910]

Interesting link (alexmo), from article:


The binding of magnesium and calcium are particularly helpful for shave soaps in hardwater areas, tho I wonder if it's cost effective compared to citric acid. I wonder what exactly the pH is affecting in performance.

According to the Soap Crafter website:
Costing approximately $81.95 per 500 grams of this chemical... is it truly cost-effective for the small production soap maker?
"Adjust pH of formula to pH 6.0 or below." is also stated on the product page... might work for creams or lotions, but it doesn't appear to be a feasible ingredient for soaps; either liquid or bar.
Sodium Phytate